Representatives from the 29 countries, including Russia, Belarus, Serbia, Cuba, Brazil and Venezuela, as well as 10 African and 12 Asian countries, signed the agreement as founding members.
The organization's headquarters will be located in Shanghai, Chinese state agency Xinhua said.
The signing ceremony was held in Shanghai on the eve of the annual World Artificial Intelligence Conference, where Chinese President Xi Jinping is expected to outline an ambitious vision for Beijing's role in global AI governance.
China proposed the creation of a World AI Cooperation Organization at last year's conference but no countries had formally announced membership until now.